Automatic fluid fill apparatus for subsurface conduit strings



A g- 1962 E. H. CLARK, JR., ETAL 3,051,246

AUTOMATIC FLUID FILL APPARATUS FOR SUBSURF'ACE CONDUIT STRINGS Filed April 15, 1959 2 Sheets$heet l &

INVEN 0i; m n 57 H. :44? Mb. 1 BY JZ/U/M/ 0. A/Z/THIHA/ WWW Aug. 28, 1962 E. H. CLARK, JR., ETAL 3,

AUTOMATIC FLUID FILL APPARATUS FOR SUBSURFACE CONDUIT STRINGS Filed April 13, 1959 2 Sheets-Sheet 2 I N VEN TOR5 fig/V557 6' 14 26 die JUL /4/V 0. (f/7774a Arraeusrs.

hired; tees a ateur @fliee 3,5l,2d Patented Aug. 28, 1962 3,051,246 AUTOMATIC FLUm FILL APPARATUS F'GR SUBSURFACE CONDUHT STRINGS Earnest H. Clark, In, Downey, and luiian D. Keithahn,

Anaheim, Caiii, assignors to Baker Oil Tools, lnc., Los Angeles, Calif., a corporation of California Filed Apr. 13, 1959, Ser. No. 805,975

14 Claims. (Cl. l65226) The present invention relates to subsurface well bore equipment and more particularly to apparatus for automatically filling a conduit string as it is being lowered through fluid in a well bore.

An object of the invention is to provide improved apparatus adapted to form part of a conduit string and capable of permitting the conduit string to fill automatically with the well bore fluid as it is being lowered in the well bore, the apparatus also being capable of functioning as a back pressure valve permitting downward flow of fluid through the conduit string, but preventing upward or return flow of fluid therethrough.

Another object of the invention is to provide apparatus adapted to form part of a conduit string and capable of permitting the conduit string to fill automatically with the well bore fluid as it is being lowered in the well bore, the apparatus automatically closing to prevent further filling of the conduit string in the event the conduit string is being lowered too rapidly in the well bore, or a blow-out tends to occur.

A further object of the invention is to provide apparatus adapted to form part of a conduit string and capable of permitting the conduit string to fill automatically with the Well bore fluid as it is being lowered in the well bore, the apparatus being conditioned to prevent further upward flow of fluid in the conduit string by circulating fluid downwardly through the conduit string about a predetermined rate.

An additional object of the invention is to provide apparatus adapted to form part of a conduit string and capable of permitting the conduit string to fill automatically with the well bore fluid as it is being lowered in the well bore, as well as allowing fluid to be circulated downwardly through the conduit string, the apparatus being capable of being conditioned to function as a back pressure valve preventing further upward fluid flow in the conduit string.

This invention possesses many other advantages, and has other objects which may be made more clearly apparent from a consideration of several forms in which it may be embodied. Such forms we shown in the drawings accompanying and forming part of the present specification. These forms will now be described in detail for the purpose of illustrating the general principles of the invention; but it is to be understood that such detailed description is not to be taken in a limiting sense, since the scope of the invention is best defined by the appended claims.

Referring to the drawings:

FIGURE 1 is a longitudinal section through an apparatus disposed in a well bore, conditioned to allow fluid to flow upwardly in the conduit string;

FIG. 2 is an enlarged longitudinal section through the apparatus disclosed in FIG. 1, with certain parts latched in position to prevent upward flow of fluid in the conduit string while permitting downward flow therethrough;

FIG. 3 is a view similar to FIG. 2, with the apparatus in closed position;

FIG. 4 is an enlarged cross-section taken along the line 4-4 on FIG. 2;

FIG. 5 is a cross-section taken along the line 55 on FIG. 3;

FIG. 6 is a longitudinal section through a somewhat modified form of the apparatus;

FIG. 7 is a cross-section taken along the line 7-7 on FIG. 6.

As disclosed in the drawings, an apparatus A is provided which can be incorporated in a conduit string B, such as a string of casing or tubing, that is to be lowered through fluid in a well bore C, and in which such conduit string may be cemented in the well bore. As shown in FIGS. 1 to 5, inclusive, the apparatus can be constituted as a collar adapted to connect upper and lower sections 10, 11 of the conduit string in spaced relation. Thus, the collar A includes a main tubular member or housing 12, which may be made of an upper section 13 and a lower section 14 threadedly attached to one another. The upper section may have a threaded box 15 for threadedly securing the housing to the lower pin 16 of the upper section it) of tubing or conduit string; whereas the lower section 14 may have a threaded pin 17 for threaded reception with a threaded box 18 on the lower conduit string or tubing section 11.

As the conduit string B is lowered through the fluid in the well bore, such fluid is initially and normally permitted to flow upwardly through the collar A, to fill the conduit string with the Well bore fluid. Such upwardly flowing fluid will pass through passages 19 provided in an insert or spider 20 disposed within a counterbore 21 in the lower tubular member section 14, this insert or spider consisting essentially of a central hub 22 from which arms 23 radiate, the outer portions 24- of the arms projecting upwardly to form an inner guide surface 25 for the depending tubular stem 26 of a valve member 27 having a head 28 integral with the stem. The valve member is normally urged in an upward direction to engage its head 28 with a companion downwardly facing valve seat 29 formed on the upper tubular member section or housing 13 by a helical compression spring 3%) surrounding the stem 25, with its upper end engaging the head 28 and its lower end engaging the upper end 31 of the bottom section 14. The fluid flowing upwardly through the passages 19 between the spider arms 23 will also pass upwardly around the stem 26 and inwardly to the interior of the valve member 27 through a plurality, such as a pair, of side ports or passages 32. The fluid will flow from the interior of the valve member through a central passage 33 and into the tubing or conduit string section 10 thereabove.

The upwardly flowing fluid cannot pass upwardly directly into and through the valve stem 26 since the bore 34 of the latter is closed by a plug 35, the upper end of which initially terminates below the side port 32, and the lower end of which is initially disposed adjacent to the central hub 22 of the insert or spider 20. The plug is retained initially in such position within the valve stem by a shear pin 36 extending between the plug and stem, leakage of fluid around the exterior of the plug being prevented by a suitable side seal 37, such as a rubber or rubber-like 0 ring, disposed in a groove 33 in the upper portion of the plug or barrier and sealingly engaging the wall of the bore 34 in the valve stem 26.

As described hereinbelow, the shear pin 36 may be disrupted to release the plug 35 from the valve stem 26, whereupon the plug can shift upwardly in the valve stem to a position in which it is disposed across the side ports 32, with the seal ring 37 sealingly engaging the inner Wall of the valve head 28 above the ports 32. The plug is retained in such position by a latch or detent device, which includes a pair of opposed lock pins or detents 40 slidable radially in a transverse bore 41 in the central portion 42 of the plug and urged outwardly by a helical compression spring 43 in the bore engaging the inner ends of the pins or detents 40. When the plug 35 is disposed in its lower position with the shear pin 36 intact, the outer ends of the pins merely engage the inner wall 34 of the valve stem 26.

However, after the shear pin has been disrupted, the plug 35 moves upwardly within the valve member to the position disclosed in FIG. 2, in which position the lock pins or detents 40 will be disposed opposite a circumferentially continuous internal groove 44 in the stem 26, the spring 43 urging the pins 40o'utwardly into such groove, and thereby locking or latching the plug 35 in its upper position within the valve member 27, in which the ports 32 are closed.

In the use of the apparatus, the shear pin 36 is initially intact, locating the plug 35 downwardly within the stem 26 and projecting below the lower end 45 of the latter, with the upper end of the :plug disposed below the side ports 32. The spring 30 then urges the valve head 23 upwardly into engagement with its companion seat 29. As the conduit string is lowered through the fluid in the well bore, the fluid will flow upwardly through the spider 2%, around the valve stem 26, and in through the side ports 32 to the interior valve member, discharging upwardly from the central passage or outlet 33 of the valve member into the tubular member 13 thereabove for continued upward flowing through the conduit string B. By restricting the combined area through the side ports 32, or by restricting the area through the valve outlet 33, the rate of flow of the well bore fluid into the conduit string B can be controlled so that the filling rate preferably does not exceed a preferred'value. The upwardly flowing fluid will also tend to. maintain the valve head 28 in engagement with its seat 23.

After the conduit string B has been lowered to the desired extent in the well bore, downward circulation through the conduit string is instituted. Such downward circulalation at a relatively low rate can occur without afiecting the condition of the apparatus illustrated in FIG. 1, in which the shear pin 36 is intact, in that the downwardly circulating fluid can pass through the central passage 33 in the valve head 28 and through its side ports 32, and around the valve stem 26 for continued downward flowing through the spider and bottom tubular member section 14 into the tubular string 11 and the well here. For that matter, relative downward flow of fluid may occur as a result of elevating the conduit string from the slips (not shown) at the top of the well bore, as in adding additional tubular sections to the conduit string during lowering of the latter in the well bore. The relative downward movement of the fluid in the conduit string can occur under the condition just referred to without shearing the pin 36, whereupon the conduit string can continue to be lowered in the well bore and the apparatus will controllably allow the conduit string to fill with the well bore fluid.

However, upon circulating fluid downwardly above a predetermined rate, the plug 35 will engage the spider hub 22 and a suflicient back pressure will be imposed on the upper end of the valve member 27 to shear the pin 36, whereupon the valve head 28 will move downwardly away from its seat 29 against the compressive force of the spring 30, compressing the latter. Such downward movement of the valve member will slide it downwardly along the plug 35 until the latter is relatively shifted across the ports 32 with its seal ring 37 sealingly engaging the inner wall of the head above the ports and with its latches or detents 40 disposed in the groove 44, which will efiectively secure the plug 35 to the valve member 27 for movement therewith (FIG. 2). The downwardly circulating fluid will now Pass around the exterior of the head 28, which may have circumferentially spaced longitudinal grooves 50 therein, to increase the circulating area around the head, the downward fluid flowing around the valve stem 26 and through the spider or insert 20 into the conduit string 11 therebelow. In moving downwardly, the valve stem 26 is guided by the inner guide surfaces of the spider arms 24, which actually form portions of a cylindrical surface.

Upon the cessation of downward circulation through the conduit string, the spring 30 shifts the valve member 27 and the plug upwardly as a unit, to engage the valve head 28 with its seat 29, thereby preventing upward flow of fluid through the well bore (FIG. 3). However, if the conduit string is to be cemented in the well bore, the downward pumping of cement slurry or the like can occur, such downwardly moving cement slurry shifting the valve and plug combination 27, 35 downwardly away from the seat against the force of the spring 36*, the cement slurry flowing around the valve member 27 and through the spider 20 for discharge from the tubing string B at a point therebelow, the cement slurry then flowing upwardly through the annulus around the string B to the desired elevation. When the downward pumping of the cement slurry ceases, its return flow into the conduit string is preclud ed by virtue of the upward movement of the valve head 28 into engagement with its companion valve seat 29. The fluid cannot flow upwardly through the valve member ports 32 since they are closed by the plug 35, which also continues to close the central passage 34 through the valve member 27.

The apparatus A can be converted into a back pressure valve to prevent any upward flow of fluid therethrough in the event a blowout condition occurs in the well bore C during lowering of the conduit string B therewith. With the shear pin 36 intact and the parts of the apparatus occupying the relative position disclosed in FIG. 1, a blowout condition in the well bore would cause fluid to flow upwardly at an excessive rate, which would build up a pressure acting on the underside of the plug 35 suflicient to shear the pin 36 and shift the plug 35 upwardly in the valve member bore 34 to dispose it across the ports 32 and close the latter, the plug being held in the port closing position by the movement of the latch pins 40 into the circumferential groove 44 in the valve stem 26. Thus, continued upward passage of fluid through the apparatus is automatically prevented.

As disclosed in FIGS. 6 and 7, the apparatus can be constituted as a shoe D rather than a collar by constituting the lower tubular member section 14a as a guide which is threaded upwardly in the upper section 13, the guide having a lower nose 51 tapered in a downward and inward direction to steer the conduit string past obstructions that might be encountered in the well bore during lowering of the conduit string B therewithin. If desired, arms 23a corresponding to the arms 23 of the spider portion in the other form of the invention may be formed integrally in the guide, the valve stem 26 sliding within a comparion bore 25a in the upper portion of the guide and the lower end of the plug 35 being adapted to engage the lower, inner ends of the arms 23a. The radial and longitudinal passages 19a in the guide 14:: through which fluid can pass are readily evident from the drawings.

The appartus has been found especially useful in relatively small diameter well bores, or slim holes, in which tubing is used as the conduit string or casing. By way of example, the conduit string B may be constituted as 2 /8 inch OD tubing. Because of its relatively small internal diameter, it is comparatively difficult to fill it with the well bore fluid from the surface of the well bore. The apparatus illustrated permits automatic filling of such relatively small diameter tubing at a proper rate while preventing excessive upward flow, as might occur in the event a blowout condition presents itself in the well bore. By way of example, the shear pin 36 may be of a size as to allow upward filling of the conduit string if the filling flow rate does not exceed 65 gallons per minute. However, if such flow rate is exceeded, the shear pin is disrupted and the plug 35 will shift upwardly to close the side ports 32, thereby precluding further upward flow of fluid in the tubing string B.

In the event the tubing B is being run in the well bore at too high a rate, such that the upward flow rate through the apparatus tends to exceed the aforementioned indicated rate of 65 gallons per minute, which would be attained with a tubing speed in excess of 10 feet per second, the shear pin 36 would also be disrupted and the plug 35 moved upwardly and latched in position to close the flow ports 32.

Downward flow of fluid through the tubing string below the indicated value of 65 gallons per minute would permit downward circulation through the apparatus without shearing the pin 36, but flow rate in excess of the amount given would also result in disruption of the shear pin and a downward shifting of the valve member 27 along the plug 35 to close the ports 32, after which downward flow of fluid could only occur around the valve member 27. Cessation of such downward flow of fluid would cause the valve member 27 and its plug 35 to move upwardly as a unit to place the valve head 28 in valve closing engagement against its companion seat 29.

The inventors claim:

1. In apparatus for controlling the flow of fluid in a conduit string positionable in a well bore: a tubular member having a valve seat therein; a valve member in said tubular member movable to and from engagement with said seat and responsive to pressures on opposite sides thereof; means providing an open by-pass passage around said valve member when said valve member is engaged with said seat; means for closing said by-pass passage; releasable means retaining said closing means in a position opening said passage; and means for retaining said closing means in closed position after release of said releasable means.

2. In apparatus for controlling the flow of fluid in a conduit string positionable in a well bore: a tubular member having a valve seat therein; a valve member in said tubular member movable to and from engagement with said seat and responsive to pressures on opposite sides thereof; means providing an open by-pass passage through said valve member when said valve member is engaged with said seat; means for closing said by-pass passage; releasable means retaining said closing means in a position opening said passage; and means for retaining said closing means in closed position after release of said releasable means.

3. In apparatus for controlling the flow of fluid in a conduit string positionable in a well bore: a tubular member having a valve seat therein; a valve member in said tubular member movable to and from engagement with said seat and responsive to pressures on opposite sides thereof; means providing an open by-pass passage through said valve member when said valve member is engaged with said seat; means shiftable relatively along said valve member to close said lay-pass passage; releasable means retaining said closing means in a position opening said passage; and means for retaining said by-pass passage closing means in closed position after release of said releasable means.

4. In apparatus for controlling the flow of fluid in a conduit string positionable in a well bore: a tubular member having a valve seat therein; a valve member in said tubular member movable to and from engagement with said seat and responsive to pressures on opposite sides thereof, said valve member having a bore therein and a by-pass passage therethrough through fluid can flow when said valve member engages said seat; and means within and normally closing said bore at one side of said by-pass passage and shiftable in said here to .a position closing said by-pass passage.

5. In apparatus for controlling the flow of fluid in a conduit string positionable in a well bore: a tubular member having a valve seat therein; a valve member in said tubular member movable to and from engagement with said seat and responsive to pressures on opposite sides thereof; means providing an open by-pass passage through said valve member when said valve member is engaged with said seat; means shiftable relatively along said valve member to close said by-pass passage; and means for securing said closing means to said valve member in its by-pass passage closing position.

6. In apparatus for controlling the flow of fluid in a conduit string positionable in a well bore: a tubular member having a valve seat therein; a valve member in said tubular member movable to and from engagement with said seat and responsive to pressures on opposite sides thereof, said valve member having a bore therein and a by-pass passage therethrough which fluid can flow when said valve member engages said seat; means Within and closing said bore and shiftable in said bore to a position closing said by-passage; and means for securing said closing means to said valve member in its by-pass passage closing position.

7. In an apparatus for controlling the flow of fluid in a conduit string positionable in a well bore: a tubular member having a valve seat therein; a valve member in said tubular member movable to and from engagement with said seat and responsive to pressures on opposite sides thereof; means providing an open by-pass passage through said valve member when said valve member is engaged with said seat; means shiftable relatively along said valve member to close said by-pass passage; means releasably securing said closing means to said valve member in a position in which said by-pass passage is open; and means for securing said closing means to said valve member in its by-pass passage closing position.

8. In apparatus for controlling the flow of fluid in a conduit string positionable in a well bore: a tubular member having a valve seat therein; a valve member in said tubular member movable to and from engagement with said seat and responsive to pressures on opposite sides thereof, said valve member having a bore therein and a by-passage therethrough through which fluid can flow when said valve member engages said seat; means within and closing said bore and shiftable in said bore to a position closing said by-pass passage; means releasably securing said closing means to said valve member in a position in which said by-pass passage is open; and means for securing said closing means to said valve member in its hy-pass passage closing position.

9. In apparatus for controlling the flow of fluid in a conduit string positionable in a well bore: a tubular member having a valve seat therein; a valve member in said tubular member movable to and from engagement with said seat and responsive to pressures on opposite sides thereof, said valve member having a by-pass passage that includes a central bore through said valve member and a side port in the valve member establishing communication between the exterior of said valve member and said bore; a barrier in said bore initially in a position permitting fluid to by-pass through said passage when said valve member engages said seat, said barrier being shiftable in said bore to a position closing said passage.

10. In apparatus for controlling the flow of fluid in a conduit string positionable in a well bore: a tubular member having a valve seat therein; a valve member in said tubular member movable to and from engagement with said seat and responsive to pressures on opposite sides thereof, said valve member having a by-pass passage that includes a central bore through said valve member and a side port in the valve member establishing communication between the exterior of said valve member and said bore; a barrier in said bore; releasable means initially securing said barrier to said valve member in a position permitting fluid to flow through said passage when said valve member engages said seat, said means being releasable to enable said barrier to be shiftable in said bore to a position closing said passage; and means coupling said barrier to said valve member in said passage closing position.

11. In apparatus for controlling the flow of fluid in a conduit string positionable in a well bore: a tubular member having a valve seat therein; a valve member in said tubular member movable to and from engagement with said seat and responsive to pressures on opposite sides thereof, said valve member having a by-pass passage that includes a central bore through said valve member and a side port in the valve member establishing communication between the exterior of said valve member and said bore; a barrier in said bore; shear means initially securing said barrier to said valve member in a position permitting fluid to flow through said passage when said valve member engages said seat, said shear means being disruptable v to enable said barrier to be shiftable in said bore to a posi tion closing said passage; said valve member having a recess therein; and a lock pin on said barrier shiftable into said recess to couple said barrier to said valve member in said passage closing position. I

12. In apparatus for controlling the flow of fluid in a conduit string positionable in a well bore: a tubular member having a valve seat therein; a valve member in said tubular member movable upwardly into engagement with said seat and downwardly from engagement with said seat and responsive to pressures on opposite sides thereof, said valve member having a hy-pass passage that includes acentral bore through said valve member and a side port in said valve member establishing communication between the exterior of said valve member and said bore; a barrier in said bore projecting from the lower end of said valve member; releasable means initially securing said barrier to said valve member in a position permitting fluid to flow upwardly through said passage When said valve member engages said seat; a support within said tubular member adapted to be engaged by said barrier to release said releasable means and enable said barrier to be shifted relatively upwardly in said bore to a position closing said passage; and means coupling said barrier to said valve member in said passage closing position.

13. In apparatus for controlling the flow of fluid in a conduit string positionable in a well bore: a tubular member having a valve seat therein; a valve member in said tubular member movable upwardly into engagement with said seat and downwardly from engagement with said seat, said valve member having a by-pass passage that includes a central bore through said valve member and a side port in said valve member establishing communication between the exterior of said valve member and said bore; a barrier in said bore projecting from the lower end of said valve member; shear means initially securing said barrier to said valve member in a position permitting fluid to flow through said passage when said valve member engages said seat; means within said tubular member adapted to engage the downwardly projecting portion of said barrier to enable fluid pressure above said valve member to urge said valve member downwardly to disrupt said shear means and shift said valve member downwardly of said barrier to a position in which said barrier closes said passage; and means coupling said barrier to said valve member in said passage closing position, whereby said valve member and barrier are movable as a unit to and from said seat.

14. In apparatus for controlling the flow of fluid in a conduit string positionable in a well bore: a tubular memher having a valve seat therein; a valve member in said tubular member movable upwardly into engagement with said seat and downwardly from engagement with said seat, said valve member having a bypass passage that includes a central bore through said valve member and a side port in said valve member establishing communication between the exterior of said valve member and said bore; a barrier in said bore projecting from the lower end of said valve member; shear means initially securing said barrier to said valve member in a position permitting fluid to flow through said passage When said valve member engages said seat; means within said tubular member adapted to engage the downwardly projecting portion of said barrier to enable fluid pressure above said valve member to urge said valve member downwardly to disrupt said shear means and shift said valve member downwardly of said barrier to a position in which said barrier closes said passage; said valve member having a recess therein; and a lock pin movable laterally in said barrier and into said recess to couple said barrier to said valve member, whereby said valve member and barrier are movable as a unit.

References Cited in the file of this patent UNITED STATES PATENTS 

